Field
The present disclosure relates to a balloon catheter system and method for treating biological vessels and, more particularly, to an angioplasty balloon catheter which includes a grid of fibers attached to, or integrated within a wall of the balloon. The fibers are less elastic than the balloon material and as such, when the balloon is inflated beyond a predetermined pressure a plurality of balloon regions protrude from the grid formed by the fibers.
Description of the Related Art
Percutaneous transluminal angioplasty (PTA) is a procedure in which a balloon catheter is inserted through an artery and guided to the region of lumen narrowing. The balloon is inflated to force the plaque material (typically fat and calcium) against the wall of the artery to open the vessel lumen and improve blood flow.
Angioplasty balloons are typically cylindrical when inflated and have different lengths and diameters to conform to different vessel sizes. The balloons are inflated at high pressure, normally between 8-20 atmospheres, in order to overcome the resistance of the plaque and achieve luminal expansion.
Standard balloons (also referred to as plain balloons) are the most commonly used technique for dilation of a lesion in a blood vessel (angioplasty); however, standard balloons suffer from several disadvantages.
Since the diameter and composition of stenotic regions of an artery are not typically uniform, inflation of a standard balloon in a vessel leads to non-uniform (axially and radially) expansion. Variability in the lesion composition (lesions can be composed of a mixture of hard and soft plaque material) will lead to variability in resistance to dilation along the lesion and to balloon over expansion in the least resistant regions of the vessel. As a result, standard balloons can apply excessive forces to less resistant regions of the lesion thus traumatizing the vessel wall (e.g. dissections) and yet do not apply enough forces to resistant plaque regions to enable effective dilation thereof.
Trauma to the vessel wall is associated with poor long term clinical results and can accelerate or induce restenosis in the treated areas. In addition, major dissections, such as flow limiting dissections require stenting further complicating the procedure.
Attempts to solve the aforementioned limitations of standard balloon catheters by increasing forces on resistant plaque region via cutting or scoring elements (blades/wires) positioned on the balloon surface (e.g. U.S. Publication No. 20040143287 and U.S. Publication No. 20060085025) were somewhat successful but did not adequately solve problems resulting from non-uniform balloon expansion. In addition, cutting and scoring balloons are not designed to avoid traumatizing the vessel walls, but instead to control the trauma to the vessel walls by inducing controlled and predictable dissections.
Thus, there is a need for a high pressure angioplasty balloon catheter capable of effectively opening resistant plaque regions without traumatizing the vessel walls in less resistant plaque regions.